Heating the Greenhouse using passive solar methods?

wide angle view of GH interior

I like this wide angle view of the inside of the greenhouse

I want to heat the greenhouse in the winter using passive solar methods. There is nothing growing in it so far this winter but I’m doing some experimenting to see how warm I can get it (my goal is around 32°F or warmer) at night. To this end I’m experimenting using compost to help heat it, putting some barrels with water in them to act as a heat sinks and I’m insulating the structure inside a little better so as not to lose so much heat at night. If the sun shines, it gets between 70-80° in the day right now (which is delightful) and I’d like to keep some of that heat in at night and not lose it. Of course I had the opposite problem last summer when it got too hot but that’s another problem I’ll address this summer!

GH inside winter

The center bench has compost underneath it in a raised bed

The compost pile is only 1/2 a yard so is probably not enough to keep it significantly warmer  inside the greenhouse but what if it adds a degree or two? I’ll take it. Everything helps. The compost pile got up to 112°F  while the surrounding soil in the two raised beds is 40°F. Not that I’m planting in the compost but it shows it is significantly warmer. Now it has cooled down to 60°. The night temperatures are still below freezing inside.

Since I didn’t have a chance make shutters for the screen windows before winter set in, my friend, Jody, thought of putting plastic on both sides of the open screen ‘windows’ to trap warm air and slow the heat loss. I’ve done that now.

bubble wrap down on windows

The vents are covered with plastic and bubble wrap is on all the windows

I just put bubble wrap on the windows to hopefully act as insulation to slow the loss of heat at night as well. Plus I added bubble wrap on the ceiling between the rafters. Elodie said probably a lot of heat is loss up there through the uninsulated fiberglass roof. Now the green house looks like a  bubble wrap house on the inside! The night temperatures are still below freezing inside.

I painted the rain barrels black and filled them with  water to act as heat sinks

I painted the rain barrels black and filled them with water to act as heat sinks

I also have 4 rain barrels that I painted black and filled with water and installed hose bibs on the bottom so I can empty the water out at the end of winter. I put them under the growing tables and the night temperatures are still below freezing inside. And lastly I plugged up a lot of leaks where the roof meets the rafters.

Did it work? Are my nighttime temperatures above freezing? NOPE. I’ve only been able to keep it about 5 degrees warmer than the outside temperature which make me go to plan B.

What is plan B? Try planting only super cold hardy winter greens and see what happens. Stayed tuned…

It took a village to build my greenhouse!

final greenhouse

I haven’t posted much about the greenhouse I’ve been building but now that it is basically done (I still have a few more things to do) I want to share the greenhouse raising from the ground up and give thanks to those who contributed with their time, labor and knowledge. It has truly taken a village to build it! It all started in January of 2010 and has taken 3 years to complete it. Many, many thanks to the following people:

First, thanks to Caleb for coming out in January 2010 and jackhammering the holes out to set the posts. I was hoping to get it done back them by spring of 2010 so I wanted to get an early start-what a dreamer I was… 3 years passed because of everyone being sooo busy with other things (including me) and then this year in 2013 the magic happened.

Thanks Lava for helping me make it gopher proof, mouse proof, putting down the weed cloth, unloading the gravel for the floor and much more I’m sure I forgot about. Thanks Jacob, (Lava’s son) who generously put in 2 days of work on it when he was here visiting his mom earlier this year.

Thanks Elodie for helping in various tasks including putting the headers up in the framing, window framing, gopher proofing the raised beds, putting the sink in and much more as well.

And a big thanks to Tom Rivers. Without him I still would be at the beginning stages. What can I say about Tom? He is a great friend who came over week after week every Friday on his day off this year and with his constructions skills actually made it happen. Together we were able to build it or I should say I helped him build it. Both him and I are a lot alike-we became obsessive about building it, like dogs with their bones and we wouldn’t let go of it till it was completed. Truly a labor of love. Thank you thank you Tom!

I am now putting on the finishing touches and buttoning it up for winter to see how warm I can get it inside at night using passive methods-more on that later…But for now here is a pictorial on building it.

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The Greenhouse is Coming Along!

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Two winters ago I started planning my future greenhouse. I wasn’t sure if I would build a hoop house or a traditional greenhouse but then a friend, Kate, donated 10 big windows from her sunroom when she replaced them. I got a great screen door from someone else and I got some large wood panels from another friend. SO I decided to build a more traditional style of greenhouse. Then when I rented a Bobcat to regrade my driveway, I leveled an area for the future greenhouse and ALSO leveled and scraped the ground for adding more garden space. My friend, Caleb and I put the posts in last January, jackhammering the frozen holes out and then he got a full-time job teaching and could not help anymore. So instead I concentrated on expanding the garden last spring. Which I did—to the tune of an additional 1000 square feet!

Meanwhile the greenhouse posts just sat there and some were twisting badly.  This spring, another friend of mine, Tom, offered to help me finish it and has carpentry experience. So Tom is helping me finish building my greenhouse (or should I say I’m helping him) every Friday morning from 8am-12pm. I’ve set a deadline for myself to try to finish it by May 15th. Hopefully we will make it by then. It is moving along nicely. So far we have replaced most of the twisted uprights, got the rafters and purlins done for the roof, the west side framing is almost done, the window frames are built on the south side but we won’t put the windows in until the end, the bottom sides of the future garden beds are done on both the south and north sides and are redwood. We will frame the windows on the north side this week. Still have to get the roofing material, the wall material that is not going to be windows and the side with the door done. I am so excited that it is finally moving along! PROGRESS!!

New Gardens-new bruises!

I love hearing about someone putting in a new garden or adding on to their existing one or adding another big feature in their gardens. Are any of you doing something new and exciting in your gardens this year? I would love to hear about your projects!

For me, I’ve bitten off a lot. Between putting in a new greenhouse and adding on a huge new section, I have my hands full. And I forget I’m not 30 yrs old anymore (tell that to my brain) and my body let’s me know it too after a hard day building, hauling, shoveling, digging-you get the picture. Today I dropped a 2 x 6 on my nose while 8 feet on a ladder while working on the greenhouse. Luckily, I didn’t break it! I should own stock in Advil…

Greenhouse progress

Finally progress on the greenhouse! I finished digging out 6 of the 8 holes over the last 2 weeks when we had some warm days and Caleb came by last Sunday (a week ago) and we finished digging the last 2 holes with his jack hammer. Yesterday (Friday), I set all 8 posts by myself. After consulting with a contractor friend to see if I could set the posts in cement, he told me yes but bury them in dirt afterwards to insulate them-brilliant! Boy was it a long day but nothing a warm Epsom Salt bath can’t help. I’m really happy as I can work on framing it when we have a nice day this winter-especially since I came down with a nasty cold today…